The present invention pertains to control systems for controlling the exterior lights of a vehicle and components that can be used with such a control system.
Modern automotive vehicles include a variety of different lamps to provide illumination under different operating conditions. Headlamps are typically controlled to alternately generate low beams and high beams. Low beams provide less illumination and are used at night to illuminate the forward path when other vehicles are present. High beams output significantly more light and are used to illuminate the vehicle""s forward path when other vehicles are not present. Daytime running lights have also begun to experience widespread acceptance. In addition, super bright high beams have been proposed for use on fast rural roads. Foul weather lights, such as fog lights, are also commonly used. Other exterior vehicle lights include tail lights, brake lights center-mounted stop lights (CHMSLs), turn signals, back-up lights, cargo lights, puddle lights, license plate illuminators, etc.
Laws in various countries regulate vehicle illumination, and vehicle manufacturers must build cars that comply with these regulations. For example, regulations set forth by the United States Department of Transportation (DOT) regulate the light emissions of a vehicle""s high beam headlamps. Various state regulations are used to control the amount of glare experienced by drivers due to preceding vehicles (other vehicles traveling in the same direction) and oncoming vehicles (vehicles traveling in the opposite direction).
Known vehicle high beam headlamp emissions in accordance with the DOT regulations limit the intensity to 40,000 cd at 0xc2x0, 10,000 cd at 3xc2x0, 3250 cd at 6xc2x0, 1500 cd at 9xc2x0, and 750 cd at 12. An example of an emission pattern meeting this regulation is illustrated in FIG. 1 of U.S. Pat. No. 5,837,994, entitled CONTROL SYSTEM TO AUTOMATICALLY DIM VEHICLE HEADLAMPS, issued to Joseph Scott Stam et al. on Nov. 17, 1998, the disclosure of which is incorporated herein by reference. In order to avoid an illuminance of 0.1 foot candles (fc) incident on another vehicle at these angles, the vehicle high beam headlamps should be dimmed within 700 feet of another vehicle if the vehicles are at an angle of 0xc2x0, within 350 feet of another vehicle if the vehicles are at a horizontal position of 3xc2x0, and 200 feet of the other vehicle if the position of the other vehicle is at an angle of 6xc2x0 to the longitudinal axis of the controlled vehicle. It can thus be seen that a preceding vehicle directly in front of the controlled vehicle (i.e., at an angle of 0xc2x0) will need to be identified well prior to the controlled vehicle catching up to the preceding vehicle, although the distance by which the controlled vehicle""s headlamps must be dimmed for a preceding vehicle can be somewhat less than for an oncoming vehicle because glare from behind is usually less disruptive than oncoming glare.
In order to automatically control the vehicle headlamps, various headlamp dimmer control systems have been proposed. In order to prevent drivers of other vehicles from being subjected to excessive glare levels, an automatic headlamp dimmer system must sense both the headlamps of oncoming vehicles as well as the tail lights of preceding vehicles. Some systems that effectively detect headlamps are unable to adequately detect tail lights. Most prior systems are unable to distinguish nuisance light sources, such as reflectors, street signs, streetlights, house lights, or the like, from light sources that require headlight control. Accordingly, these systems are subject to undesirable dimming of the high beams when no other traffic is present and turning on the high beams when other vehicles are present. In addition to the undesirable performance, it is difficult for prior systems to comply with the legal requirements as described above for high beam control while avoiding unnecessary dimming of the vehicle headlamps.
Fog lights are examples of other vehicle lights that are difficult to control automatically. Vehicles are known to include forward and rearward directed fog lights. In Europe, it is known to provide a very bright red or white light on the back of the vehicle, which is illuminated under foggy conditions. The fog lights must be turned ON as soon as the fog reduces visibility by a predetermined amount and must turn OFF when the fog drops below that density. A reliable method of automatically controlling such fog lights has not been available.
Accordingly, there is a need for a more reliable and intelligent automatic lamp control for a vehicle.
According to one aspect of the present invention, a control system is provided to control exterior lights of a controlled vehicle. The control system comprises an imaging system configured to image the scene forward of the controlled vehicle, and a control circuit for processing the image of the scene obtained from the imaging system and for controlling the exterior lights to change their beam pattern in response to objects detected in the processed scene, the control circuit disables automatic control of the exterior lights in response to activation of the vehicle windshield wipers.
According to another aspect of the present invention, a control system is provided to control exterior lights of a controlled vehicle. The control system comprises an imaging system configured to image the scene forward of the controlled vehicle, and a control circuit for processing the image of the scene obtained from the imaging system and for controlling the exterior lights to change their beam pattern in response to objects detected in the processed scene, the control circuit disables automatic control of the exterior lights when the vehicle windshield defroster is operating at full speed.
According to another aspect of the present invention, a control system is provided to control exterior lights of a controlled vehicle. The control system comprises an imaging system configured to image the scene forward of the controlled vehicle, and a control circuit for processing the image of the scene obtained from the imaging system and for controlling the exterior lights to change their beam pattern in response to objects detected in the processed scene, the control circuit disables automatic control of the exterior lights when snow is detected.
According to yet another embodiment, a method of detecting snowfall or fog outside a vehicle is accomplished. The method comprises the steps of: sensing light levels forward above the vehicle; comparing the relative brightness of the light levels forward and above the vehicle; and determining that it is snowing or foggy when a ratio of the relative brightness forward of the vehicle to that above the vehicle reaches a threshold.
According to another aspect of the present invention, a control system is provided to control the headlamps of a vehicle. The control system comprises an ambient light sensor for sensing the ambient light outside of the vehicle, and a control circuit for varying the beam pattern of daytime running lamps in response to the ambient light level sensed by the ambient light sensor.
According to another aspect of the present invention, a control system is provided to control the brightness of the tail lamps of a vehicle. The control system comprises an ambient light sensor for sensing the ambient light outside of the vehicle, and a control circuit for varying the brightness of the tail lamps in response to the ambient light level sensed by the ambient light sensor.
According to yet another aspect of the invention, a headlamp control system is provided for controlling the headlamps of a controlled vehicle that comprises: an imaging system configured to image the scene forward of the controlled vehicle; a control circuit coupled to the imaging system for identifying and determining the brightness of light sources in images obtained from the imaging system and for controlling the headlamps to vary a beam pattern of the headlamps as a function of the brightness of light sources within the images; and a user input mechanism coupled to the control circuit for allowing a user to adjust a sensitivity at which the control circuit will control the headlamps in response to light sources within the images.
According to yet another aspect of the invention, a headlamp control system is provided for controlling the headlamps of a controlled vehicle that comprises an imaging system configured to image the scene forward of the controlled vehicle and to detect an ambient light level outside the vehicle, and a control circuit coupled to the imaging system for determining an ambient light level outside the vehicle, for identifying and determining the brightness of light sources in images obtained from the imaging system, and for controlling the headlamps to vary a beam pattern of the headlamps as a function of the brightness of light sources within the images when the ambient light level is above a threshold level.
According to another aspect of the present invention, a control system is provided to control exterior lights of a vehicle. The control system comprises an image array sensor including a plurality of pixels, an optical system configured to image the scene forward of the controlled vehicle onto the image array sensor, the optical system including a forwardmost surface, and a control circuit for processing the image of the scene obtained from the image array sensor and for controlling the exterior lights in response to objects detected in the processed scene, wherein the optical system includes a hydrophilic coating on the forwardmost surface.
According to yet another aspect of the present invention, a vehicle control system is provided to control the brightness of continuously variable headlamps that have a brightness that varies continuously between a high beam state and a low beam state. The control system comprises an imaging system configured to image the scene forward of the controlled vehicle, a control circuit for identifying and determining the brightness of light sources in images obtained from the imaging system and for controlling the brightness of the headlamps as a function of the brightness of light sources within the images, and an indicator coupled to the control circuit and positioned inside the vehicle for indicating to the driver the relative brightness of the headlamps.
According to another aspect of the invention, an imaging system for a vehicle is provided that comprises an image sensor having an array of pixels and at least one other component, and an optical baffle disposed between the images sensor and a scene to be imaged for preventing light from the scene from reaching the at least one other component.
According to a further aspect of the invention, a headlamp control system for a vehicle is provided that comprises an imaging system configured to image the scene forward of the controlled vehicle, a switching mechanism for manual input of a driver""s selection of a feature affecting the control of the vehicle headlamps, and a control circuit coupled to the switching mechanism and the imaging system for identifying and determining the brightness of light sources in images obtained from the imaging system and for controlling the brightness of the headlamps as a function of the brightness of light sources within the images and as a function of the status of the switching mechanism.
Another aspect of the present invention is to provide a headlamp control system for a vehicle that comprises a control circuit coupled to the vehicle headlamps for fading the headlamps of the vehicle to an off state in response to the turning off of the vehicle ignition or exiting the vehicle.
According to another aspect of the invention, a control system is provided to control exterior lights of a vehicle. The control system comprises an image array sensor including a plurality of pixels, an optical system configured to image the scene forward of the controlled vehicle onto the image array sensor, the optical system including a forwardmost surface, and a control circuit for processing the image of the scene obtained from the image array sensor and for controlling the exterior lights in response to objects detected in the processed scene, the optical system includes a photocatalytic coating on the forwardmost surface.
Another aspect of the present invention is to provide a control system to control the headlamps of a vehicle. The control system comprises a manually actuated switch mechanism for receiving input from a driver to temporarily increase the brightness of the vehicle headlamps in a flash-to-pass state, an ambient light sensor for sensing the ambient light outside the vehicle, and a control circuit coupled to the ambient light sensor and the manually actuated switch mechanism for varying the beam pattern of the headlamps during the flash-to-pass state in response to the ambient light level sensed by the ambient light sensor.
According to yet another aspect of the present invention, a control system is provided to control the headlamps of a vehicle where the vehicle has a microwave receiver for receiving signals from satellites. The control system comprises a control circuit for receiving signals from the microwave receiver indicative of the location of the vehicle, the control circuit controls the headlamps to limit the perceived brightness of the headlamps from exceeding a predetermined level less than their capacity when the vehicle is travelling on a residential street.